1. Field of the Invention
The present invention relates to a video signal recording and reproducing apparatus which can simultaneously record and reproduce a video by using a disk apparatus.
2. Description of the Related Art
A video tape recorder (VTR) has heretofore been used as a home-use video recording apparatus. As is well known, a VTR receives a broadcast program transmitted by a broadcasting station via an antenna, records the program and then reproduces the program. That is to say, having once finished the recording operation of a predetermined program, the VTR rewinds the tape on which the program has been recorded and then reproduces the received and recorded program to be watched.
A currently available VTR cannot record and reproduce a video simultaneously. For example, assuming that a broadcast program which starts at 10 o""clock and ends at 12 o""clock is now being received and recorded by a single VTR, it is impossible to reproduce and watch the broadcast program from the beginning from 11 o""clock on, while continuing receiving and recording the program. It is much less impossible to perform a trick play reproducing operation (e.g., a fast-forward reproducing operation or a backward reproducing operation) of a recorded video of a program which is now being received and recorded. On the other hand, a technique which is called xe2x80x9cfollowing reproducing operationxe2x80x9d is currently utilized for a live broadcast relayed by a broadcasting station. In accordance with this technique, a video which has been transmitted to a broadcasting station is slightly delayed and then delivered substantially in real time. However, in such a case, it is necessary to use either a plurality of VTRs or an optical disk apparatus of a special type in which a recording head and a reproducing head are separately provided, for simultaneously performing the recording and the reproducing operations. If a plurality of VTRs are simultaneously used, then it becomes adversely complicated to operate these apparatuses. On the other hand, the use of such an optical disk apparatus of a special type disadvantageously increases the costs.
According to the present invention, a video signal recording and reproducing apparatus is provided. The video signal recording and reproducing apparatus of the invention includes: receiving means for receiving a television signal; image compression means for compressing an amount of information per unit time of the received continuous video signal, writing means for intermittently writing a compressed video signal, obtained as an output of the image compression means, onto a hard disk apparatus via a magnetic head; reading means for intermittently reading out the written compressed video signal from the hard disk apparatus via the magnetic head; decoding means for restoring the read compressed video signal into an original video signal; display means for displaying the restored video signal; and control means for controlling the writing means and the reading means such that writing the video signal onto the hard disk apparatus and reading an arbitrary video signal, which was previously written onto the hard disk apparatus, from the hard disk apparatus are performed apparently simultaneously and continuously.
In one embodiment, a compressed video signal which was recorded at an earliest time is sequentially updated by a newly received and obtained compressed video signal.
In another embodiment, an audio signal, as well as a compressed video signal, is recorded onto the hard disk apparatus.
In still another embodiment, the video signal recording and reproducing apparatus further includes instruction means for starting and/or finishing recording a compressed video signal onto the hard disk apparatus.
In still another embodiment, the video signal recording and reproducing apparatus further includes instruction means for starting and/or finishing reproducing a compressed video signal from the hard disk apparatus.
In still another embodiment, the instruction means for starting recording a compressed video signal onto the hard disk apparatus is instantaneously driven manually.
In still another embodiment, the instruction means for starting recording a compressed video signal onto the hard disk apparatus is driven by timer means.
In still another embodiment, the instruction means for finishing recording a compressed video signal onto the hard disk apparatus is driven by timer means.
In still another embodiment, the instruction means for starting reproducing a compressed video signal from the hard disk apparatus is instantaneously driven manually.
In still another embodiment, the display means displays at least a time difference between a time at which a video signal which is being reproduced was recorded and a current time, in addition to a video.
In still another embodiment, the display means displays at least a current time and a time at which a video signal which is being reproduced was recorded, in addition to a video.
In still another embodiment, the video signal recording and reproducing apparatus includes operation means for setting a normal reproduction, a fast forward reproduction, a backward reproduction or a slow reproduction as a reproduction mode.
In still another embodiment, the display means simultaneously displays a received video signal and an output of the decoding means which was previously recorded, reproduced and decoded.
In still another embodiment, the video signal recording and reproducing apparatus further includes television signal detection means for determining whether or not the receiving means has received a normal television signal and writing onto the hard disk apparatus is enabled only when the television signal detection means has detected a normal television signal.
According to another aspect of the present invention, a video signal recording and reproducing apparatus is provided. The video signal recording and reproducing apparatus includes: image compression means for digitizing an input continuous video signal and audio signal, thereby compressing an amount of information per unit time; writing means for intermittently writing a compressed video signal, obtained as an output of the image compression means, onto a hard disk apparatus via a magnetic head; reading means for intermittently reading out the written compressed video signal from the hard disk apparatus via the magnetic head; decoding means for restoring the read compressed video signal into an original video signal; and display means for displaying the restored video signal, thereby reading out predetermined video and audio signals at a predetermined time.
According to still another aspect of the present invention, a video signal recording and reproducing apparatus is provided. The video signal recording and reproducing apparatus includes: image compression means for digitizing an input continuous video signal and audio signal, thereby compressing an amount of information per unit time; writing means for intermittently writing a compressed video signal, obtained as an output of the image compression means, onto a hard disk apparatus via a magnetic head; reading means for intermittently reading out the written compressed video signal from the hard disk apparatus via the magnetic head; decoding means for restoring the read compressed video signal into an original video signal; display means for displaying the restored video signal; and sound recognition means for recognizing an audio signal. In the video signal recording and reproducing apparatus, predetermined video and audio signals are read out at a point of time when the sound recognition means recognizes a predetermined sound.
According to still another aspect of the present invention, a video signal recording and reproducing apparatus is provided. The video signal recording and reproducing apparatus includes: image compression means for digitizing an input continuous video signal and audio signal, thereby compressing an amount of information per unit time; writing means for intermittently writing a compressed video signal, obtained as an output of the image compression means, onto a hard disk apparatus via a magnetic head; reading means for intermittently reading out the written compressed video signal from the hard disk apparatus via the magnetic head; decoding means for restoring the read compressed video signal into an original video signal; and display means for displaying the restored video signal. In the video signal recording and reproducing apparatus, a video signal at an arbitrary point of time is retrieved for an arbitrary time period by an operation of a viewer from video signals which are being received or video signals which were previously recorded, and information for prohibiting overwriting data of the retrieved video signal is added to the retrieved video signal so as to be stored into the hard disk apparatus.
In one embodiment, when a video signal retrieved by an operation of a viewer is saved, search information required for the viewer to search for a desired video signal later is added to the video signal to be saved, and after the video signal which was previously retrieved and saved has been searched for and read out based on the search information, the read compressed video signal is decoded to be displayed on the display means.
In another embodiment, the video signal recording and reproducing apparatus includes at least an output terminal for outputting digital data which has been recorded onto the hard disk apparatus to the outside of the apparatus. In the video signal recording and reproducing apparatus, a video signal retrieved by a viewer is transferred to another recording apparatus through the output terminal.
According to still another aspect of the present invention, a video signal recording and reproducing apparatus is provided. The video signal recording and reproducing apparatus includes: image compression means for digitizing an input continuous video signal and audio signal, thereby compressing an amount of information per unit time; writing means for intermittently writing a compressed video signal, obtained as an output of the image compression means, onto a hard disk apparatus via a magnetic head; reading means for intermittently reading out the written compressed video signal from the hard disk apparatus via the magnetic head; decoding means for restoring the read compressed video signal into an original video signal; and display means for displaying the restored video signal. In the video signal recording and reproducing apparatus, while compressing a video signal which is being received and writing the compressed video signal onto the hard disk apparatus, a video signal which was previously recorded is read out and decoded into an original video signal, and after an amount of data of the decoded video signal has been reduced, the video signal is subjected to an image compression again and written onto the hard disk apparatus.
According to still another aspect of the present invention, a video signal recording and reproducing apparatus is provided. The video signal recording and reproducing apparatus includes: receiving means for simultaneously receiving television signals from a plurality of channels; image compression means for compressing an amount of information per unit time of the received continuous video signals from the plurality of channels; writing means for intermittently writing each compressed video signal, obtained as an output of the image compression means, onto a hard disk apparatus via a magnetic head; reading means for intermittently reading out the written compressed video signal from the hard disk apparatus via the magnetic head; decoding means for restoring the read compressed video signal into an original video signal; and display means for displaying the restored video signal. In the video signal recording and reproducing apparatus, while compressing video signals from the plurality of channels which are being received and writing the compressed video signals onto the hard disk apparatus, a video signal which was previously recorded from a particular channel is read out.
According to still another aspect of the present invention, a video signal recording and reproducing apparatus is provided. The video signal recording and reproducing apparatus includes: receiving means for simultaneously receiving television signals from a plurality of channels; synthesis means for synthesizing the received television signals from the plurality of channels into one screen; image compression means for compressing an amount of information per unit time of the continuous video signal which has been synthesized by the synthesis means; writing means for intermittently writing a compressed video signal, obtained as an output of the image compression means, onto a hard disk apparatus via a magnetic head; reading means for intermittently reading out the written compressed video signal from the hard disk apparatus via the magnetic head; decoding means for restoring the read compressed video signal into an original video signal; and display means for displaying the restored video signal. In the video signal recording and reproducing apparatus, a plurality of video signals are synthesized into one screen, subjected to an image compression and then written onto the hard disk apparatus.
By utilizing the above-described configurations, it is possible to provide an apparatus which can independently perform a trick play reproducing operation (e.g., a fast-forward reproducing operation or a backward reproducing operation) of a recorded part of a broadcast program which is now being received, while compression encoding and recording the broadcast program. As a result, it is possible to start watching a recorded part of a program without waiting for the program to end as is done in the recording and reproducing operations performed by a conventional single VTR. In addition, even when a viewer initially starts watching a program at a time much later than the broadcast start time of the program, the viewer can finish watching the program substantially at the same time as the broadcast end time by additionally utilizing a fast-forward reproducing function in the middle of the reproducing operation.
According to the present invention, it is possible to provide an apparatus which can perform a normal reproducing operation or a trick play reproducing operation (e.g., a fast-forward reproducing operation or a backward reproducing operation) of a recorded part of a broadcast program which is now being received, while recording the broadcast program by using a universal hard disk apparatus without using a plurality of VTRs or an expensive optical disk apparatus for which a recording head and a reproducing head are separately provided. As a result, it is possible to start watching a recorded part of a program without waiting for the program to end, as is necessary in the recording and reproducing operations performed by a conventional single VTR. In addition, even when a viewer initially starts watching a program at a time much later than the broadcast start time of the program, the viewer can finish watching the program substantially at the same time as the broadcast end time by additionally utilizing a fast-forward reproducing function in the middle of the reproducing operation, so that a considerable amount of time can be saved. Moreover, in the case where a viewer cannot help stopping watching a program in the middle of the program, even if the program still continues when the viewer resumes watching the program, the viewer can reproduce and watch the program from the scene which was broadcast when the viewer left, while continuing recording the program. Furthermore, in the case where a viewer watches a first program while recording a second program on a different channel, it is possible to instantaneously start watching the second program from the beginning thereof at a time after the first program ends and before the second program ends.
Thus, the invention described herein makes possible the advantage of providing a video signal recording and reproducing apparatus which can simultaneously record and reproduce a television signal.
This and other advantages of the present invention will become apparent to those skilled in the art upon reading and understanding the following detailed description with reference to the accompanying figures.